Internal-combustion engine



B. V. E. NORDBERG.

INTERNAL COMBUSTION ENGINE.

APPLICATION FILED APR-.14, 1914- Patented Dec. 21,

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BRUNO V. E. NOBDBERG, F MILWAUKEE, WISCONSIN.

rN'rEamm-comnosrron Enema To all whom it may concern:

Be it known that I, Bruno V. E. NonnnERo, a citizen of the United States, residmg at Milwaukee, in the county of Milwaukee and State of Wisconsin, have invented certain new and useful Improvements in Internal-Combustion Engines, of which the following is a specification.

My present invention pertains to an improved internal combustion engine and to the method of operating the same, wherein the fuel is ignited by being intermixed with highly heated compressed air in the combustion chamber of the engine, as contradistinguished from that type of engine wherein the gas, usually produced from a readily gasifiable fuel, is intermixed with air, compressed, and then exploded.

My improved method consists essentially in heating charges of oil in a feed chamher in the presence of compressed air, and thereafter ejecting the charge in an atomized condition, into the highly-heated compressed air in the combustion chamber wherein it is burned, causing the engine to operate.

The operation is such that during the compression stroke of the piston a portion of the compressed air passes into the fuelheating chamber where it intermingles with the fuel, vaporizing the more highly volatile particles of the charge and finally, through the explosion thereof, due to the increase in temperature incident to the higher degree of compression toward the end of the compression stroke, and also to the increase in the volume of oxy en incident to the presence of the compressed air in said fuel heating chamber, the fuel is ejected in an atomized form or condition from the fuel heating chamber into the compressed air, where it ignites and imparts motion to the piston.

In the annexed drawings, I have disclosed more or less diagrammatically in Figure 1 an engine adapted to operate under or carry out the method herein claimed, it being understood that the apparatus may be readily varied so long as it is capable of carrying out the cycle of operations above outlined and hereinafter more specifically set forth in detail, and in Figs. 2 and 3 I have shown certain details of the invention.

In the drawings, 1 denotes the engine body, .2 the combustion chamber or cylinder Specification of Letters Patent.

Patented Dec. 21, 1920. 191a. eeriai'no. 831,800.

thereof provided with an exhaust port 3, and 4: the piston, cut away at one side as at 5, to admit of the free passage of compressed air into the cylinder (when the p1ston is in its lowest position) from a scavenging port or passage 6, which terminates at its lower end in a compression chamber 7, formed in the lower or crank portion of the engine body or casing, which latter is provided with an air-intake valve 8. The oil is fed from a reservoir 9, through suction pipe 10, past-check valve 11, into a pump chamber 12. The pump plunger or piston is designated by 13, and

is operated in any convenient manner from the crank-shaft of the engine, but preferably in, such a manner that the stroke of the plunger maybe varied by the engine governor or by hand, for the purpose of varying the quantity of fuel to conform to variations of load on the engine. Normally, the pump piston is withdrawn by-a spring 14, and is moved inwardly against the tension of the spring by the lever 15 fulcrumed' on a fixed portion of the engine frame, with the interposition of an eccentric 16 provided with a handle 17 through which the stroke of the pump may be varied, or the pump thrown out of action; or whereby the pump may be operated by hand in starting.

Lever 15 is connected by rod 18 with an eccentric strap 19 or a governor 20-connected and driven through suitable gearing, as shown, from the crank shaft 21 of the engine.

The stroke of the pump may be varied either by adjusting the clearance on the end of the plunger and the end of the operating lever, which is effected through eccentric 16, or by changing the eccentricity of the governor. It is. of course, plain that by moving the handle 17 back and forth, the point of connection between the lever 15 and the rod 18 being fixed, the pump will be operated by hand. Eccentric 16 may, however, be thrown to such position that the fulcrum of lever 15 is lifted high enough so that on the down stroke of the lever its free end does not come into contact at all with the pump plunger and the latter becomes inactive.

22 denotes the discharge valve of the pump, the valve being forced ofi its seat (against which it is normally held by a spring 23) by the fuelwhich is forced downwardly by the pump, the fuel discharging to a space or chamber 24 (or it may be a pipe, the pump being remotely located), the lower end of which is normally closed by an upwardly-seating check valve 25. The space immediately below the check valve terminates in a restricted opening 26, which has the effect of injecting the oil into a fuel-heating chamber 27, preferably provided (in the form illustrated) with a plurality of restricted nozzle-shaped openings 28. A single discharge opening may be employed, and in fact has been employed with good results but seemin lya plurality of openings gives more satis actory'results, as the charge is more evenly and generally discharged throughout the combustion chamber or cylinder.

The cycle of operation'is as follows:

The engine of the two-cycle type is started by any convenient means, such as compressed air, alternately injected and ex hausted from the space above the piston 4, or by an electric starting device, or the like. On the up-stroke air is drawn through valve 8, into the crank case and air compressed in the chamber 2 above the piston to a comparatively high pressure. On the down stroke this air expands back to its initial pressure, which is that of the atmosphere, while the air entrapped in the crank case or chamber is compressed to a comparatively low pressure. When the piston approaches its lowest point it uncovers port 6 and the compressed air from the crank case rushesthrough said port into the cylinder, coming into contact with the cut-away face 5, sweep ing through the cylinder and out through port 3 carrying out all burned gases, should there be any present, leaving the cylinder full of clear air which is compressed on the next up-stroke of the piston. This, of course, is .common to all two-cycle engines.

The eccentric or eccentric strap 19 (or other equivalent device) is so adjusted that during the initial part of the upstroke, while the air above piston 4.- is being compressed, the pump piston 13 forces oil past discharge valve 22 and spray nozzle or device 26 into the fuel-heating chamber 27. This chamber is heated by combustion of previous charges of fuel during the operation of the engine or during the process of starting by contact with highly heated compressed air in the upper end of the cylinder above the piston, so that the fuel in part, or the more highly volatile portion thereof, is volatilized or gasified in chamber 27 This chamber is, however, so small that it does not contain enough air to support combustion, and the fuel cannot'pass outwardly through the small opening or nozzle 28, for the reason that during the upward movement of the piston a counter pressure of air is exerted and the compressed air passes inwardly through such opening. The area of chamber 27 is so proportioned that when piston 4 reaches a position at or near the upper end of its stroke, enough compressed air will have been forced into the chamber to support combustion of that part of the fuel which has been vaporized, or partly so; consequently, such vaporized fuel ignites and, as a result of the explosion which then takes place, in said chamber, the heated unburned fuel will be driven out in a very finely-divided condition through the restricted openings into the cylinder. There, by reason of the spraying, it is intimately intermixed with the heated compressed air and instantly ignites, driving the piston downwardly.

By making the opening 28 of proper size, the flow of the atomized fuel from the fuelheating chamber 27 may be so regulated that the time of burning is extended so as to prevent the rise of pressure of the burning mixture, or to limit it to any desirable degree. Experiments have shown that by varying the size of the opening 28 any desired combustion pressure may be obtained, whether it be equal to, greater, or even less than the final pressure of the air compressed in the combustion space of the cylinder. Practice has demonstrated that the force of the explosion in the fuel heating chamber 27 1s powerful enough to thoroughly clean out said chamber, even if the fuel carries or precipitates, when heated, solid particles, whether combistible or non-combustible, and that the latter are so finely divided as to pass out through the exhaust without depositing on the interior surface of the cylinder.

In Fig. 2 I have shown the detail of the opening from the fuel heating chamber whichhas produced the most satisfactory results. It may be said to have the general form of a conical or counterbored nozzle, wherein the discharge opening 28 is approximately one-sixteenth of an inch in diameter with the thickness of thewall in which the opening isformed approximately one sixtyfourth inch, while the counterbored portion is about one-fourth of an inch in diameter. The thinner the wall in which the opening is formed the better the results, or in other words, the thinner the discharge edge of the opening, the more efficacious the atomizing of the fuel ejected therethrough.

By making the heating chamber of high grade steel such as nickel steel containing a high percentage of nickel, or making it of self hardening tool steel, the thickness of the wall may be reduced so that the discharge opening may be brought almost to a sharp edge.

It is to be noted that with the construction ofthe engine as set forthand operated in the manner described, there are no moveeann ing parts other than the piston exposed to the burning fuel or charge, and that no valves, shutters or the like are necessar or employed with the discharge opening of the fue -heating chamber.

Having thus described my invention, what claim is:

1. In an internal combustion engine, the combination of a cylinder and piston; a fuel-heating chamber in communication with the combustion end of said cylinder through restricted openings; and means for forcing a charge of fuel into said heating chamber as the air compressed within the cylinder is likewise forced into said chamber.

1 2. In an internal combustion en ine, the combination of a cylinder; a fue -heating chamber in free and open communication with saidcylinder at all times through re stricted ports or openings; means for spraying a charge of fuel into said chamber; a pump for forcing fuel to said means; a piston working in the cylinder and adapted to force compressed air into the chamber simultaneously with the introduction of the fuel thereinto; and driving connections for the pump operated from and in timed relation with a moving portion of the engine.

3. In an internal combustion engine, the combination of a cylinder; a fuel heating chamber in open communication with said cylinder at all times through a plurality of restricted ports or openings, said ports being counterbored and presenting a thin wall or edge at the discharge opening thereof; means for spraying fuel into said chamber; a pump for forcin fuel to said means; a piston working in the cylinder and adapted to force compressed air into the chamber simultaneously with the introduction of the fuel thereinto; and driving connections for the pump operated from and in timed relation with a moving portion of the engine.

In testimony whereof I have signed my name to this specification in the presence of two subscribin witnesses.

B UN 0 V. E. NORDBERG. Witnesses:

E. C. BAYERLEIN, C. SCHRETKA; 

